Manufacture of molds for casting metals.



CAROLINE J. M. IBOHL, or BROOKLYN, NEWYYORK.

MAIbTUFAGTURE OF MOICDS FOR CASTING METALS.

No'Drawing.

' To all whom it may concern:

Be it known that I, CAROLINE J. M. Box-11., a citizen of the UnitedStates, and res1ding at Brooklyn, in the county of Kings and State ofNew York, have invented certain new and useful Improvements in theManufacture of Molds for Casting Metals, of which the following is aspecification, such 'as will enable those skilled in the art to which itappertains to make and use the same.

This invention relates to molds'for casting metals, and the objectthereof is to provide an improved mold for this purpose by means of.whicli'the delicate.outlines and designs of a finely wrought pattern canbe perfectly reproduced in a mold from said pattern; a

further object being to provide a mold for the purpose specified whichwill stand or resist the heat of a furnace and also the heat of themetals poured into it without being fractured or broken.

In the practice of my invention I take equal quantities of plaster ofParis and ashes, which, being thoroughly ground or pulverized andthoroughly mingledor reduced to a thick liquid of the consistency ofcream by stirring thereinto and mingling therewith a requisite amount ofwater. In this operation there will be formed on the surface of theliquid a greater or less amount of dirt or refuse matter which should beskimmed off. The liquid thus formed is poured over or around the desiredpattern in a suitable receptacle to form the desired mold; and after theliquid has been allowed to set or become hard, which operation takesabout half an hour, the mold so formed is removed from the pattern, orthe pattern from the mold. The mold is then slowly dried in a lowtemperature of from 100 to 200 Fahrenheit, after which the mold iscovered or painted with melted lard either on the inner side only, or onboth the inner and outer sides according to the thickness of the mold,after which said mold is put in an oven or furnace the temperature ofwhich isgradually raised to from 800 to 1000 Fahrenheit, according tothe thickness or mass of the mold, after which said mold is The plasterof Parisand ashes contain some objectionable or interfering substanceswhich will be burnt out ,in

the above operation, and this completes the mold which is now ready foruse.

The above method of making a mold has i an advantage over other andsomewhat simi- Specifitzation of Letters Patent.

stances may be used.

Patented Feb. 10, 1914.

Application filed May 1, 1913. Serial No. 764,891;

advantage especially when undercutpatterns are used. A mold made in thismanner will give a finer result 1n castmg various metals and especiallybrass which is one of the hardest metals to cast on account of thequantity of fumes or gases which it discharges in the operation ofcasting. The ob ject of covering or painting the mold with melted lardand then heating and drying it 1n an oven, as hereinbefore described, isto prevent the mold from absorbing moisture. and this renders myimproved mold much more efficient than others of this class especially,in the operation of casting brass, for which purpose no practical moldhas heretofore been made, though many have claimed to be able to do so.By means of myimproved process a mold can also be made in much less timethan is ordinarily necessary, this process requiring but one or twohours,

in some cases, in which other processes would require days. A mold madein this manner will also stand anymetal .or mixture of metals, thisresult being also accomplished by reason of the extremely porous qualityof the mold.

This invention is an improvement onv stances which it is very difiicultto remove,

but which is entirely obviated by the improved process herein described.I

The use of my improved process is not confined to the purpose or objectherein set out, as the same may be applied in making or manufacturingother articles or devices, and although I have described the use of lardfor the purpose of painting the mold after it is formed and beforedrying or heating, it will be apparent, that other oleaginous sub:

Having fully described my invention what I claim as new and desire tosecure by Letters Patent is A The method of making molds and otherarticles herein described, which consists of 10 then heating said moldin an oven, gradually raising the temperature to-"fro'm 800 to 1000Fahrenheit. v

In testimony that I claim the foregoing as my invention I have signed.my name in presence of the subscribing Witnesses this 15 29th day ofApril, 1913.

CAROLINE J. M. BOHL.

Witnesses: 1 v

C. 'MULREANY, S. ANDREWS.

